Re: Chip control of auto transmission shift points?

DrollTroll wrote:
"Mike Romain" <romainm@xxxxxxxxxxxx> wrote in message
news:48e7b668$0$31074$9a6e19ea@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
DrollTroll wrote:
Awl --

Are the shift points of small-car (eg, Honda Fit, 07) auto tranny's chip
controlled?

If so, I would imagine the shift points, both down and up, can be readily
changed.
Can I get the dealer to do it?
I feel it shifts *down* too soon on hills, with gas, etc, and would like
to
delay shifts -- esp. since I can always downshift by hand, if nec.

If not, is there another way to delay downshifting? Something I could
kluge/wire in? A dealer-type job?

Thanks,
I highly doubt any dealer would install an engine blowing chip. Most
engines and trannies for that matter too do not like to be lugged.
Things break when that happens. Gas mileage goes to crap when you lug
it too.

I'm not talking about installing anything additional.
I'm basically asking *how the shift points are controlled*, and if they can
then be adjusted, particularly in delaying downshifts.

It also depends on what "lug" means. I'm not talking about lugging the
engine until it sputters and smokes.
And, since everything is slower and lower doing this, I think mechanical
wear would not be an issue.

It is torque load that explodes stuff. That is why most owners manuals
say to lock out (do not use) top gear or Overdrive when climbing hills
or towing. Check yours. Folks can and do blow the tranny gears to
pieces, literally.


Lastly, mpgs drop drastically when the engine downshifts.
I know this from a scangauge installed on my pickup. The engine certainly
"feels better", say, when going up a hill, and the tranny naturally drops
down a gear, but the mpg's drop 30% as well.

Scanners are only sold to make mechanics money by giving lots of
'misleading' and averaging info.

You are going up a hill. That burns more gas. Simple eh.

I can tell you for sure that lugging an engine in too high a gear drinks
way more gas than running with no load on it. In my Jeep and my friends
Jeeps with oversized tires and 'mileage' gears, so we are comparing a
carb and FI engines (actually several Jeepers I know have tried this
with the same results), we get about 5 mpg 'better' running in 4th gear
at 65 mph at 2300 rpm that we get running the same route to our camping
area in 5th or OD running 65 mph at 1750 rpm.

The 1750 rpm is lugging our engines. No smoke or anything. Sure we
still have 'pull', but it takes too much on the gas pedal to adjust for
little slopes or wind where the lower gear only takes a twitch on the
gas pedal.


This is one reason mpg's in city driving are so bad.


Not really. You have to be always on the gas pedal accelerating and on
the brake decelerating in the city. This burns gas and wears out brakes.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com
.

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